1. Field of the Invention
The present invention relates to a display device, and more particularly, to a liquid crystal display device.
2. Discussion of the Related Art
Among various display devices, a cathode tube ray (CRT) has been widely used for monitors in television, measuring instrument and digital assistant equipment. However, due to its large weight and size, the CRT has been inapt for effectively responding to recent demands for downsizing and weight reduction of electronic appliances.
A liquid crystal display (LCD), which is advantageously light weighted and small sized, has been actively developed in an effort to replace the CRT. According to the recent development, the LCD can sufficiently function as a flat display device, and the demand therefor is increasing.
In general, a low cost and high performance line film transistor LCD (TFT-LCD) uses an amorphous silicon thin film transistor as a switching device. At present, the LCD is oriented towards a high resolution display that operates in a video graphic array (VGA) mode with the maximum resolution of 640×480 pixels, a super video graphic array (SVGA) mode of 800×600 pixels or in an extended video graphic array (XVGA) mode of 1024×768 pixels.
The development and application of the TFT-LCD industry have been accelerated due to the recent increase in size and resolution of the TFT-LCD. Significant efforts are devoted to process simplification and yield rate improvement to achieve productivity increase and low cost.
An LCD utilizes the electro-optic properties of a liquid crystal material injected into the LCD panel. In order to display the image on the front surface of the LCD panel, a backlight is required as a light source that uniformly irradiates the back of the LCD panel. The backlight is necessary because the LCD is non-luminous and without a self luminescent property unlike a plasma display panel (PDP) or a field emission display (FED).
A related art LCD will be described in reference to the appended drawings. FIG. 1 is a layout view of the LCD of the related art, and FIG. 2 is a sectional view taken along the line I-I′ of FIG. 1. As shown in FIGS. 1 and 2, the LCD of the related art includes scan lines 11 extending in one direction; data lines 13 and 13a extending in a direction intersecting the scan lines 11, and thin film transistors (TFTs) 15 formed adjacent the intersecting portions between the scan lines 11 and the data lines 13. The TFTs each have a gate electrode extending from the scan line 11 and source and drain electrodes formed of the same material as the data lines 13. The LCD further includes pixel, electrodes 17 electrically connected to the respective drain electrodes of each pixel area. The pixel electrodes 17 are shaped to overlap in part with adjacent scan lines 11 so as to be used as an electrode of a storage capacitor at each pixel area. The pixel, electrodes 17 are also shaped so as to avoid the areas at which the TFTs are formed. Electrodes 19 may be formed at the area of the storage capacitor to constitute a part of the storage capacitors.
In this construction, at each pixel, parasitic capacitors, the capacitance of which are represented by Cdp1 and Cdp2, are created between each data line 13 and each pixel electrode 17 and between each pixel electrode 17 and each data line 13a, respectively.
FIG. 3 shows a magnified plan view of the pixel electrode according to the related art. Referring to FIG. 3, the pixel electrode 17 of the related art has asymmetric right and left sections. Such an asymmetrical shape results because the pixel electrode 17 is patterned so as not to cover a portion corresponding to the TFT 15. The asymmetrical shape in the pixel electrode 17 creates a difference between the values of the parasitic capacitanes,es Cdp1 and Cdp2 between the data lines 13 and 13a and the pixel electrode 17. In the example of FIG. 3, the value Cdp2 is larger than Cdp1. Due to the asymmetric pixel electrode shape, the LCD of the related art has the parasitic capacitors between the pixel electrode and the data lines, which have different values in capacitance between the right section and the left section. The LCD of the related art suffers a drawback that,,when the LCD is operated in a dot inversion mode, the resolution of the LCD degrades.